Electromagnetic relays and methods of manufacturing



ELECTROMAGNETIC RELAYS AND METHODS OF MANUFACTURING Filed Dec. 16, 1968 I I. I)

. E6 :4 7 I5 241/ 89 89 V 6kg I -!E[ F Q I lll/ N OR flw ATTORNEYS United States Patent Oflice 3,524,153 Patented Aug. 11, 1970 US. Cl. 335202 12 Claims ABSTRACT OF THE DISCLOSURE An electromagnetic relay and method of manufacturing said relay including the steps of inserting a pair of L-shaped terminal blades through respective slots in the base of a hollow casing, so that parts of the blades project from the exterior of the base where further parts of the blades lie in contact with the base. Inserting a hollow former having a solenoid winding wound thereon, into the casing so that one axial end of the former traps the further parts of the blades against the base. Inserting a solenoid pole piece having an enlarged end portion through the former and through a hole in the base so that the enlarged end portion of the pole piece engages the end of the former remote from the base, and finally deforming the end of the pole piece remote from the enlarged portion so that the deformed portion of the pole piece engages the outer surface of the base, so that the pole piece maintains the former and therefore the blades in position.

This invention relates to a method of manufacturing electro-magnetic relays.

A method according to the invention includes the steps of inserting a pair of L-shaped terminal blades through respective slots in the base of a hollow casing so that parts of the blades project from the exterior of the base of the casing while further parts of the blades lie parallel with and in contact with the inner surface of said base, inserting a hollow former, having a solenoid winding wound thereon, into the casing so that one axial end of the former traps said further parts of said blades against said base, inserting a solenoid pole piece, having an enlarged end portion, through said former and through a hole in said base so that said enlarged end portion of the pole piece engages the axial end of the former remote from said one end of the former, and deforming the end of said pole piece remote from said enlarged portion so that said deformed portion engages the outer surface of said base and said pole piece maintains the former and therefore said blades in position.

One example of the invention is illustrated in the ac companying drawings wherein FIG. 1 is a sectional view of an electromagnetic relay, FIG. 2 is a sectional view on the line 22 in FIG. 1, FIG. 3 is an end view of the former of the electromagnet of the relay shown in FIG. 1, FIG. 4 is a sectional view on the line 44 in FIG. 1, and FIG. 5 is a view similar to FIG. 1 of a modification.

Referring to FIGS. 1 to 4 of the drawings, the relay includes a hollow moulded synthetic resin box like casing 11 including a base 12, the end of the casing 11 remote from the base 12 being open. A pair of L-shaped conductive terminal blades 13 are inserted through slots in the base 12 so that parts of the blades project from the external surface of the base 12 while further parts of the blades lie parallel to and in contact with the inner surface of the base 12.

A hollow moulded synthetic resin former 14 having a solenoid winding 15 wound thereon is inserted into the casing. One end wall 16 of the former 14 is formed with a pair of diametrically opposite, radial, outwardly directed, dovetail tags 29. The ends of the winding 15 are wound around the tags 29 respectively, and the former is inserted into the casing 11 so that the tags 29 trap the end of the windings against the blades 13 respectively, the winding 15 thereby :being electrically connected to the blades 13. In addition to trapping the ends of the windings 15 in contact with the blades 13, the former 14 traps the blades 13 in position. Moreover the former also serves to trap an L-shaped support member 17 in position in the casing, one limb 17a of the member 17 being formed with a hole and being engaged between the former 14 and the base 12 while the other limb 17b of the member 17 extends parallel with the former 14.

A cylindrical, metal pole piece 18 having an enlarged end portion 19 is inserted through the former 14, through the hole in the limb 17a of the member 17 and through an aperture in the base 12 between the blades 13. The portion 19 of the pole piece 18 engages the end of the former 14 remote from the base 12 and the other end of the pole piece 18 is then deformed to engage the outer surface of the base 12 so as to secure the former 14, the member 17 and the blades 13 in position.

The free end of the limb 17b of member 17 is formed with a tongue 21 which extends through a slot in one limb 22a of a generally L-shaped armature 22 to support the armature 22 for pivotal movement relative to the member 17. The limb 22a of the armature 22 extend generally parallel with the base I12 adjacent the portion 19 of the pole piece 18, and the limb 22b of the armature 22 extends generally parallel with the former 14 towards the base 12, the free end of the limb 22b being bent outwardly away from the former 14.

Extending through the base 12 parallel to one another but spaced apart are a second pair of terminal blades 23, 24

Secured to the blade 23, within the casing, is a contact 25 and similarly secured to the blade 24 is the free end of one of the limbs of a generally U-shaped leaf spring 26. The free end of the other limb of the spring 26 has secured thereto a contact 27 and the spring is so positioned that the spring can be flexed to move the contact 27 into and out of engagement with the contact 25. The spring 26 is such that in its rest condition the contact 27 is spaced from the contact 25. The outwardly turned portion of the limb 22b of the armature 22 engages the spring 26 and in the rest position of the spring 26, the armature 22 is pivoted relative to the member 17 to a position wherein the limb 22a of the armature is spaced from the portion 19 of the pole piece 18 by a predetermined air gap.

In use the terminal blades 13 are electrically connected in a first circuit and the terminal blades 23, 24 are connected in a second electrical circuit. Thus when the first circuit is completed the electromagnet defined by the winding 15 and the pole piece 18 is energised and the limb 22a of the armature 22 is drawn towards the portion 19 of the pole piece 18. As the limb 22a of the armature 22 is caused to pivot relative to the member 17, and the limb 22b of the armature flexes the spring 26 in a direction to close the contacts 25, 27 and thereby complete the second circuit through the blades 23, 24 and the spring 26. Upon de-energisation of the electromagnet the armature 22 is returned to its original position and the second circuit is broken by the action of the spring 26.

In use the open end of the casing 11 is closed by an insulating plate 23 which is engaged as a snap fit in the open end of the casing.

In the modification illustrated in FIG. 5, the spring 26 is physically and electrically connected to the member 17 and the terminal blade 24 is L-shaped. The terminal blade 24 is held in position by trapping the inner portion thereof between the limb 17a of the member 17 and the base 12 of the casing. Thus the contact 27 is electrically connected to the terminal blade 24 through the spring 26 and part of the member 17. Moreover, in a modification (not shown) of the relay shown in FIG. 5, one of the terminal blades 13 is dispersed with, and the respective end of the winding 15 is electrically connected to the limb 17a of the member 17, the terminal blade 24 thus being common to the contact 27 and the Winding 15. In order to effect the electrical connection of said end of the winding 15 to the limb 17a of the member 17 the end of the winding is wound around the respective tag 29 as before, but is then positioned in contact with the end wall 16 of the former 14 so that when the relay is assembled said end of the winding engages the limb 17a of the member 17.

It will be appreciated that although the relay described is a normally open relay, normally closed relays and change over relays can be manufactured in a similar manner.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A method of manufacturing an electromagnetic relay including the steps of inserting a pair of L-shaped terminal blades through respective slots in the base of a hollow casing so that parts of the blades project from the exterior of the base of the casing while further parts of the blades lie parallel with and in contact with the inner surface of said base, inserting a hollow former, having a solenoid winding wound thereon, into the casing so that one axial end of the former traps said further parts of said blades against said base, inserting a solenoid pole piece, having an enlarged end portion through said former and through a hole in said base so that said enlarged end portion of the pole piece engages the axial end of the former remote from said one end of the former, and deforming the end of said pole piece remote from said enlarged portion so that said deformed portion engages the outer surface of said base and said pole piece maintains the former and therefore said blades in position.

2. A method as claimed in claim 1 including the further step of inserting a generally L-shaped armature support member into the casing prior to the insertion into the casing of said former, so that one limb of the support member engages said base between said terminal blades, said one limb of the support member being formed with an aperture through which said pole piece subsequently extends, said one end of the former trapping said support member in position, and said pole piece serving to maintain the support member in position in addition to maintain the former and said blades in position.

3. A method as claimed in claim 1 wherein the ends of the solenoid winding extend over portions of the surface of the former presented to said further parts of the terminal blades, so that the step of inserting the former into the casing serves to engage said terminal blades with respective ends of the solenoid Winding so that said solenoid winding is electrically connected to said terminal blades.

4. An electromagnetic relay comprising, a casing including a base, a pair of generally L-shaped terminal blades extending through said base with one limb of each of the blades extending parallel to and in contact with the inner surface of the base, a hollow former carrying a solenoid winding, one axial end of said former trapping said one limbs of said terminal blades in contact with said inner surface of the base, and a solenoid pole piece, said pole piece including an enlarged head which engages the end of said former remote from said one end thereof and said pole piece extending through said former and through said base between said terminal blades and being deformed to engage the outer surface of the base, so that said pole piece serves to retain said former, and

4 therefore said terminal blades in position relative to the casing.

5. An electromagnetic relay as claimed in claim 4 further including a generally L-shaped armature support member, one limb of said support member being trapped against the inner surface of the base by said one end of the former, and having therein an aperture through which said pole piece extends, and the other limb of said member extending within said casing generally at right angles to said base.

'6. An electromagnetic relay as claimed in claim 4 wherein the ends of said solenoid winding extend over portions of the surface of said one end of the former presented to the base, said ends of the winding being trapped in engagement with said one limb of said terminal blades respectively so that said terminal blades are electrically connected to respective ends of the winding.

7. An electromagnetic relay as claimed in claim 6 wherein said base carries a further pair of terminal blades one of which carries a fixed contact and the other of which carries a movable contact, and including an armature movable in response to energis ation of the solenoid winding, movement of said armature serving to move said movable contact relative to the fixed contact to make or break an electrical circuit between said further pair of terminal blades.

8. A relay as claimed in claim 7 wherein said movable contact is secured to one limb of a generally U-shaped conductive spring, the other limb of which is secured to said other terminal blade, said armature engaging said spring, and movement of said movable contact relative to said fixed contact being permitted by fiexure of said spring.

9. A relay as claimed in claim 5 wherein said support member is conductive, thereby including a further pair of terminal blades supported by the base, one of said further terminal blades carrying a fixed contact and the other of said terminal blades being generally L-shaped, one limb of said other blade extending in contact with the inner surface of the base and being trapped in position by said former through the intermediary of said one limb of said armature support member, so that said other blade is electrically connected to said armature support member, a movable contact carried by and electrically connected to said armature support member, and an armature supported by said armature support member and movable in response to energisation of the solenoid winding, to move said movable contact into or out of engagement with said fixed contact to make or break a circuit between said further pair of terminal blades.

10. A relay as claimed in claim 9 wherein said movable contact is secured to one limb of a generally U- shaped conductive spring the other limb of which is secured to said armature support member, said armature engaging said one limb of the spring to move the movable contact.

11. An electromagnetic relay comprising, a casing, including a base, first and second, generally L-shaped, terminal blades extending through said base with one limb of each blade extending in contact with the inner surface of the base, a generally L-shaped conductive armature support positioned within the casing with one limb thereof in contact with said one limb of the second terminal blade, a hollow former carrying a solenoid winding, said one limb of the first and second terminal blades and the armature support member being trapped between the base and one axial end of the former, a solenoid pole piece including an enlarged head which engages the end of said former remote from said one end, said pole piece extending through said former, and the base end being deformed to engage the outer surface of the base, so that the pole piece serves to retain the former and therefore the terminal blades and the armature support in position relative to the casing, a third terminal blade extending through the base, and electrically connected to a fixed contact within the casing, a movable contact carried by and electrically connected to the armature support member, and an armature supported by the armature support member, the jends of said solenoid winding being electrically connected to said first and second terminal blades, and the arrangement being such that upon energisation of the solenoid winding the armature is moved relative to the casing'to move the movable contact into or out of engagement with the fixed contact so as to make or break a circuit between said second and third terminal blades. 3

12. An electromagnetic relay as claimed in claim 11 wherein the ends of said solenoid winding are trapped by said. former in contact with said one limb of said first terminal blade and said armature support member re- References Cited UNITED STATES PATENTS 2,937,250 5/1960 Onksen 335- Z 2,945,106 7/1960 Moyer 335- 3,184,564 5/1965 Ryckman 335202 3,255,327 6/1966 Wood 335-433 BERNARD A. GILHEANY, Primary Examiner H. BROOME, Assistant Examiner 

